Sawtek, Inc.

Triquint Semiconductor Corporation

Triquint, Inc.

Natalya F Naumenko

Benjamin P Abbott

Leland P Solie

Victor S Orlov

Robert Aigner

Kurt George Steiner

Marc Solal

Taeho Kook

Alan Sangone Chen

Julien Gratier

Timothy Daniel

Suzanne Combe

In embodiments, a piezoelectric acoustic wave (PBAW) device may include a substrate and a resonator comprising a plurality of electrodes coupled with the surface of the substrate. A dielectric overcoat may be disposed over the substrate and the resonator. In embodiments, and electrode in the resonator electrode may have a width that is based at least in part on a period of the resonator. By selecting the width of the electrode based at least in part on the period of the resonator, a spurious-mode of the passband of the PBAW device may be suppressed.

High coupling, low loss PBAW device and associated method

Disclosed embodiments include a surface acoustic wave device having electrode period, electrode width, and/or ratio of electrode width to electrode period varied in a prescribed manner.

High coupling, low loss saw filter and associated method

A SAW resonator with improved temperature characteristics includes a single crystal piezoelectric substrate of symmetry 3 m, providing propagation of leaky waves with quasi-shear horizontal polarization and squared electromechanical coupling coefficient exceeding 5%. A SiOoverlay having a flattened surface covers the electrode pattern. Electrode thicknesses range from about 0.1% to about 10% of an acoustic wavelength and the SiOthickness ranges between zero and 30% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (0&#xb1;3&#xb0;, &#x3bc;, 0&#xb1;3&#xb0;), with angle &#x3bc;=90&#xb0;&#x2212;&#x3bc;' and rotation angle &#x3bc;&#x2032;, which depends on material of a piezoelectric substrate and thicknesses of electrodes and SiOoverlay. Such orientations simultaneously combined with optimized thicknesses of electrodes and SiOoverlay provide for improved performance in RF applications with improved temperature characteristics.

Buried idt SAW filter having low propagation loss

A surface acoustic wave device with improved temperature characteristics includes a piezoelectric substrate of a single crystal of symmetry 3m, providing propagation of a SAW having an electromechanical coupling factor exceeding 5%, an electrode pattern on a substrate surface forming a resonator, and a SiOx overlay covering the electrode pattern. An optimized thickness of the electrodes combined with an SiOx overlay provide improved performance in RF applications with improved temperature characteristics. To suppress spurious responses the SiOx thickness is varied depending upon the relative thickness and period of the electrodes. The electrode pattern forms resonators with the silicon oxide thickness over the electrodes inversely related to the period of the electrodes of the resonators.

A SAW device includes a LiNbOsingle crystal piezoelectric substrate having an orientation defined by Euler angles (&#x3bb;,&#x3bc;,&#x3b8;), with angle &#x3bb; ranging from &#x2212;5&#xb0; to +5&#xb0;, angle &#x3bc; ranging from about &#x2212;74&#xb0; to about &#x2212;65&#xb0;, and angle &#x3b8; ranging from &#x2212;5&#xb0; to +5&#xb0;. Electrode patterns on a surface of the substrate form element resonators having a metallization ratio ranging from about 0.3 to about 0.8 and electrode thicknesses ranging from about 12% to about 17.5% of an acoustic wavelength of a strongly coupled non-leaky surface acoustic wave, excited on the surface of the substrate, if Al is used as electrode material, and in a range from about 6% to about 10% of an acoustic wavelength, if Cu is used as electrode material. Such orientations simultaneously combined with an optimized electromechanical coupling of spurious surface acoustic mode provide for improved performance in RF applications with a widened passband.

Surface acoustic wave devices using surface acoustic waves with strong piezoelectric coupling

A SAW filter includes a piezoelectric substrate of a single crystal LiNbO and SAW resonators having an electrode thickness ranging from about 8% to about 9% of an acoustic wavelength of a high velocity SAW excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from &minus;5&deg; to &plus;5&deg;, angle &mgr; in a range from about 75&deg; to about 85&deg;, and angle &thgr; in a range from 85&deg; to 95&deg;. A metalization ratio for the resonators ranges from about 0.3 to about 0.9, with resonators in a parallel arm of the filter having a metalization ratio from 1.1-1.4 times larger than the metalization ratio for resonators in the series arm of the filter. Such orientations simultaneously combined with an optimized electrode thickness and optimized metalization ratios provide an improved performance in RF applications.

Surface acoustic wave filter

A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiNbO and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 0.1% to about 8% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;,&mgr;,&thgr;), with angle &lgr; in a range from &minus;20&deg; to &plus;20&deg;, angle &mgr; in a range from about &minus;45&deg; to about &minus;10&deg;, and angle &thgr; in a range from about (&minus;1.16&lgr;&minus;1.5)&deg; to (&minus;1.16&lgr;&plus;1.5)&deg;, wherein one of angle &lgr; and &thgr; is not equal to zero degrees. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Surface acoustic wave devices using optimized cuts of lithium niobate (LiNbO3)

A surface acoustic wave device includes a piezoelectric substrate of a single crystal LiTaO and an electrode pattern provided on a surface of the piezoelectric substrate which forms a resonator having an electrode thickness in a range of about 1% to about 15% of an acoustic wavelength of a surface acoustic wave excited on the surface of the substrate. The piezoelectric substrate has an orientation defined by Euler angles (&lgr;, &mgr;, &thgr;), with angle &lgr; in a range from &minus;4&deg; to &plus;4&deg;, angle &mgr; in a range from about &minus;52&deg; to about &minus;36&deg;, and angle &thgr; in a range from about (&minus;1.365 &lgr;&minus;4)&deg; to (&minus;1.365 &lgr;&plus;4)&deg;. Such orientations simultaneously combined with an optimized propagation loss at resonant and anti-resonant frequencies provide for improved performance in RF applications.

Surface acoustic wave devices using optimized cuts of a piezoelectric substrate

A lanthanum gallium tantalate single crystal substrate, referred to as langatate, has a prescribed range of Euler angles for substrate and crystal orientation for improving signal processing for a surface acoustic wave (SAW) device. When a voltage is applied to an input interdigital transducer (IDT) of the SAW device, a surface acoustic wave is generated in the langatate piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langatate crystal cut and wave propagation directions are defined which reduce insertion loss and frequency response distortion due to SAW transduction, diffraction, and beam steering, while achieving improved temperature stability SAW device as compared to other commonly used crystal substrates. A low power flow angle and reduced level of diffraction is also achieved.

Optimal cut for SAW devices on langatate

A lanthanum gallium silicate single crystal substrate, referred to as langasite, has a prescribed range of Euler angles for substrate and crystal orientation for improving signal processing for a surface acoustic wave (SAW) device. When a voltage is applied to an input interdigital transducer (IDT) of the SAW device, a surface acoustic wave is generated in the langasite piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langasite crystal cut and wave propagation directions are defined which reduce insertion loss due to SAW transduction, diffraction, and beam steering. As a result, temperature stability for the SAW device is improved. A low power flow angle and reduced level of diffraction is also achieved.

Optimal cut for surface wave propagation on langasite substrate

A lanthanum gallium niobate single crystal substrate, referred to as langanite, has a prescribed range of Euler angles for substrate and crystal orientation for improving signal processing for a surface acoustic wave (SAW) device. When a voltage is applied to an input interdigital transducer (IDT) of the SAW device, a surface acoustic wave is generated in the langanite piezoelectric substrate. The surface acoustic wave propagates in a direction generally perpendicular to electrodes of the IDT. The langanite crystal cut and wave propagation directions are defined which reduce insertion loss and frequency response distortion due to SAW transduction, diffraction, and beam steering, while achieving improved temperature stability SAW device as compared to other commonly used crystal substrates. A low power flow angle and reduced level of diffraction is also achieved.

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Moscow, Russia

Natalya F Naumenko